Drug class
A drug class is a set of medications and other compounds that have similar chemical structures, the same mechanism of action (i.e., bind to the same biological target), a related mode of action, and/or are used to treat the same disease. In several dominant drug classification systems, these four types of classifications form a hierarchy. For example, the fibrates are a chemical class of drugs (amphipathic carboxylic acids) that share the same mechanism of action (PPAR agonist), mode of action (reducing blood triglycerides), and are used to prevent and to treat the same disease (atherosclerosis). Conversely, not all PPAR agonists are fibrates, not all triglyceride lowering agents are PPAR agonists, and not all drugs that are used to treat atherosclerosis are triglyceride lowering agents. A drug class is typically defined by a prototype drug, the most important, and typically the first developed drug within the class, used as a reference for comparison. Comprehensive systems *Anatomical Therapeutic Chemical Classification System (ATC) is the most widely used and combines classification by organ system and therapeutic, pharmacological, and chemical properties. *Systematized Nomenclature of Medicine (SNOMED) includes a section devoted to drug classification. Chemical class This type of categorization of drugs is from a chemical perspective and categorizes them by their chemical structure. Examples of drug classes that are based on chemical structures include: *β-lactam antibiotics *Benzodiazepine *Cardiac glycoside *Fibrate *Opioid *Thiazide diuretic *Steroid Mechanism of action This type of categorization is from a biochemical perspective and categorizes them by their biological target. Drug classes that share a common molecular mechanism of action by modulating the activity of a specific biological target. The definition of a mechanism of action also includes the type of activity at that biological target. For receptors, these activities include agonist, antagonist, inverse agonist, or modulator. Enzyme target mechanisms include activator or inhibitor. Ion channel modulators include opener or blocker. The following are specific examples of drug classes whose definition is based on a specific mechanism of action: *5α-Reductase inhibitors *Angiotension II receptor blocker *ACE inhibitor *Alpha-adrenergic agonist *Beta blocker *Dopamine agonist *Dopamine antagonist *Glucagon-like peptide-1 receptor agonist *Nonsteroidal anti-inflammatory drug *Proton-pump inhibitor *Renin inhibitor *Selective glucocorticoid receptor modulator *Selective serotonin reuptake inhibitor *Statin Mode of action This type of categorization of drugs is from a biological perspective and categorizes them by the anatomical or functional change they induce. Drug classes that are defined by common modes of action (i.e., the functional or anatomical change they induce) include: *Antidiuretic *Antifungal *Antimicrobial *Antithrombotic *Bronchodilator *Chronotrope *Decongestant *Diuretic *Inotrope Therapeutic class This type of categorization of drugs is from a medical perspective and categorizes them by the pathology they are used to treat. Drug classes that are defined by their therapeutic use (the pathology they are intended to treat) include: *Analgesic *Antibiotic *Anticancer *Anticoagulant *Anticonvulsant *Antidepressant *Antidiabetic *Antipsychotic *Antiviral *Sedative Amalgamated classes Some drug classes have been amalgamated from these three principles to meet practical needs. The class of nonsteroidal anti-inflammatory drugs (NSAIDs) is one such example. Strictly speaking, and also historically, the wider class of anti-inflammatory drugs also comprises steroidal anti-inflammatory drugs. These drugs were in fact the predominant anti-inflammatories during the decade leading up to the introduction of the term "nonsteroidal anti-inflammatory drugs". Because of the disastrous reputation that the corticosteroids had got in the 1950s, the new term, which offered to signal that an anti-inflammatory drug was not a steroid, rapidly gained currency. The drug class of "nonsteroidal anti-inflammatory drugs" is thus composed by one element ("anti-inflammatory") that designates the mechanism of action, and one element ("nonsteroidal") that separates it from other drugs with that same mechanism of action. Similarly, one might argue that the class of disease-modifying anti-rheumatic drugs (DMARD) is composed by one element ("disease-modifying") that albeit vaguely designates a mechanism of action, and one element ("anti-rheumatic") that indicates its therapeutic use. Examples of these amalgamated classes include: *Nonsteroidal anti-inflammatory drug *Disease-modifying antirheumatic drug Other systems of classification Other systems of drug classification exist, for example the Biopharmaceutics Classification System which determines a drug's attributes by solubility and intestinal permeability. Legal classification *For the United States legal classification, see Controlled Substances Act. *Pregnancy category is defined using a variety of systems by different jurisdictions. Category:Pharmacodynamics Category:Medicinal chemistry Category:Pharmacological classification systems